On Sat, 2025-03-22 at 01:29 +0100, Halil Pasic wrote:
As per virtio spec the fields cols and rows are specified as little endian. Although there is no legacy interface requirement that would state that cols and rows need to be handled as native endian when legacy interface is used, unlike for the fields of the adjacent struct virtio_console_control, I decided to err on the side of caution based on some non-conclusive virtio spec repo archaeology and opt for using virtio16_to_cpu() much like for virtio_console_control.event. Strictly by the letter of the spec virtio_le_to_cpu() would have been sufficient. But when the legacy interface is not used, it boils down to the same.
And when using the legacy interface, the device formatting these as little endian when the guest is big endian would surprise me more than it using guest native byte order (which would make it compatible with the current implementation). Nevertheless somebody trying to implement the spec following it to the letter could end up forcing little endian byte order when the legacy interface is in use. So IMHO this ultimately needs a judgement call by the maintainers.
The patch looks fine to me, but can you reword this message to say what you chose and why (and not have the bit about judgment call by maintainers in there)? If it sounds right, it'll be acked and merged. If not, we'll work to ensure it's all good -- so the judgment calls happen on the list, rather than mentioning this way in the commit.
Thanks,
Amit